Changes in recording electrode impedance during anaesthesia have no effect on evoked electromyographic responses

Changes in electrical impedance at the recording electrodes have been blamed for the failure of evoked electromyographic responses to return to baseline during the offset of neuromuscular block, but a relationship between electrode impedance and electromyographic responses has never been shown. In 50 fit adults, the resistive and capacitive (reactive) components of the impedance of the recording electrodes were measured during electromyographic monitoring of neuromuscular transmission under enflurane anaesthesia. In 25 patients six 1 mm-deep punctures were made in the skin under both active recording electrodes, and in the other 25 no puncture was made. Electrode impedance was measured using an impedance bridge at a current density less than 60 microA cm-2. Skin puncture made no difference either to the electrode impedance, or to the decrement from the baseline of the first electromyographic response to the train-of-four stimuli after offset of neuromuscular blockade. The electrode impedance decreased in 48 of the patients, and increased slightly in the other two patients. There was no relationship between the decrease in the T1 response from baseline and the change in electrode impedance during electromyographic monitoring.     

Respiratory and ventilatory management of critically ill children during transport

As more and more pediatric intensive care units are established throughout the country, transport systems for critically ill children assume increasing importance. This article concerns the personnel, equipment, and other requirements for a transport system and reviews the respiratory and ventilatory management of pediatric patients during transport.     

A soluble androgen receptor in the cytoplasm of the male mastomys prostate

Summary A steroid receptor protein was isolated from the cytoplasmic fraction of Mastomys prostate. Following in vivo and in vitro labelling of the tissue with tritiated testosterone or dihydrotestosterone, samples were analysed by gel exclusion chromatography or sucrose density gradient centrifugation. A steroid receptor complex was isolated on Sephadex G-200. Analysis of the steroids associated with this complex showed that the major part of the bound radioactivity was 5 -dihydrotestosterone. The binding was inhibited by unlabelled testosterone and could not be demonstrated in the liver cytosol. Using sucrose desity gradient centrifugation, the dihydrotestosterone receptor complex sedimented at 5.6 s together with heavier aggregates. In the presence of 0.4 M KCl a single complex was sedimented at 4. 6 s. The results demonstrate a receptor protein in the cytosol of the Mastomys prostate which binds to dihydrotestosterone and is comparable to that of rat prostate.     

Organ-to-plasma uptake ratio of Tl-201 in rats injected at rest or after strenuous exercise

A comparison is made of relative organ-to-plasma Tl-201 uptake in rats at rest and after exercise (2 h swimming). Organs were obtained 1/2 or 3 h after Tl-201 injection. Under the four experimental conditions, the largest uptake was found in kidneys, heart and adrenal glands. The post-exercise to rest ratio of myocardial uptake is in agreement with clinical data reported in the literature. Two extensive tissues, skeletal muscle and fat, showed a remarkable increase of Tl-201 uptake at 3 h as compared to 1/2 h in both rested and post-exercised animals. During the same time interval there was a temporal washout of Tl-201 from heart (both at rest and after exercise) and kidney (after exercise only). The findings do not support the view of a delayed myocardial uptake phase of Tl-201 during which Tl-201 would be reintroduced into the blood from other body organs.     

Dibromochloropropane and its effect on testicular function in man

This study represents the largest series to date documenting the gonadotoxic effect in humans of dibromochloropropane, a widely used pesticide. Three semen analyses, serum hormonal determinations (luteinizing hormone, follicle-stimulating hormone and testosterone) as well as genital examinations were completed for 228 workers at 2 chemical production sites and consisting of a dibromochloropropane-exposed and non-exposed cohort. Parameteric and non-parametric statistical analyses of the data sets of the sperm densities from the 2 subpopulations demonstrated statistical significance (p less than 0.10) at the short-term (1.5 years) manufacturing plant. Log transformation of the sperm count and hourly exposure data were necessary to develop meaningful statistical conclusions. The serum concentration of follicle-stimulating hormone as a group mean was significantly greater at both production sites for the exposed cohort when compared to the non-exposed participants but decreased by 10 levels of magnitude when the group demonstraing shorter but more recent exposure was compared to those from the plant with longer chemical production. Finally, a dose-response model suggested significant changes in sperm density at the short-term but more recently operated production site when more than 100 adjusted hours of exposure were exceeded, while the longer operated but longer closed facility demonstrated a significant impairment only when more than 1,000 adjusted hours of dibromochloropropane exposure were surpassed. This difference in exposure data may reflect regenerative changes in the tests once the gonadotoxic substance had been removed but exact nature of the dibromochloropropane effect and the possibility of a "no effect" concentration remain to be defined clearly.     

Joint finance--3: hope for the dark years

For this concluding article on joint finance, Jef Smith, director of social services, Kingston-upon-Thames, gathered impressions from Newcastle, regional centre for the North-East, a city with a teaching hospital and many problems.